This invention relates generally to methods for preventing diseases caused by pathogens transmitted to a mammal by an ectoparasite attached to the mammal.
Current public health measures for preventing the transmission of the Lyme disease spirochete (Borrelia burgdorferi) focus around public education and awareness of the tick vector, Ixodes dammini. Throughout the northeastern United States, where this serious zoonotic disease is common, the usual recommendations suggest avoiding woody, brushy or grassy vegetation, and performance of self-inspections for ticks following exposure to such tick-bearing habitats. Ciesielski et al., Ann. NY Acad. Sci., 539:283-288 (1988). Insect repellents may help ward off ticks (Schreck et al., J. Med. Entomol., 23:396-399 (1986)), and a product has been designed to suppress transmission by killing ticks as they feed on white-footed mice. Mather et al., Am. J. Trop. Med. Hyg., 36:609-614 (1987); and Ann. NY Acad. Sci., 539:402-403 (1988). Physical removal of embedded ticks within 24 hours also appears to prevent spirochete transmission in animal models. Piesman et al., J. Clin. Microbiol., 25:557-558 (1987).
The prompt removal of ticks requires that the ticks be found, which is not easily accomplished. Statistics show that up to 70% of those patients diagnosed as having Lyme disease reported no history of tick bite. Hanrahan et al., J. Inf. Dis., 150:489-496 (1984); and Curran et al., NY Med. Quart., pp. 18-21, 1989. Thus reliable methods are needed for preventing diseases, such as Lyme disease, which are caused by pathogen transmission by ectoparasites, such as ticks.
An object of the invention is to provide methods which may be used effectively and reliably to prevent ectoparasite-mediated disease transmission, and which may be conveniently and rapidly implemented after or during exposure to areas known or suspected to contain pathogen-bearing ectoparasites.